<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>盒子模型</title>
	<style>
		div{
			width: 100px;
			height: 100px;

			border-top: 2px solid blue;
            border-right: 2px solid red;
            border-left: 2px solid lime;
            border-bottom: 2px solid black;
			padding: 2px;
			margin-bottom: 5px;	
		}
     
        .s{
        	width: 0;
        	height: 0;
        	border-top: 100px solid blue;
        	border-right: 100px solid transparent;
        	border-left: 100px solid transparent;
        	border-bottom: 0;
        	margin-bottom: 0;
        	padding: 0;
        }
	</style>
</head>
<body>
	<div>水水水水水水水水水水水水水水水水水</div>
	<div>水水水水水水水水水水水水水水水水水</div>
	<div class="s"></div>
</body>
</html>